This invention relates to the field of railroad train cars. More particularly, it relates to an automatic handbrake release for a railroad car.
In the railroad industry two sets of brakes are used to stop railroad freight cars. The train is operated principally on an air pressure brake system. Air pressure is built up in the engine which in turn pressurizes the air brake system for each train car. This main air pressure line is connected from car to car by means of individual car hook-ups. Once the train air pressure reaches approximately 70-90 psi, the air brake system for each car is then energized and operable. A second and hereto separate handbrake system is also utilized on each car.
Each railroad freight car is also equipped with a single separate handbrake or a pair of handbrakes, one handbrake being at each end of the car. The handbrake is manually operated and may be set despite the existence of air pressure on the train car or the movement of the train. These handbrakes are set to operate individually from each other and individually from each other car on the railroad train.
One problem frequently encountered in the railroad industry is the problem of moving the train while one or more handbrakes are still set in the braked position. This could occur due to the negligence of the operators of the railroad train itself or due to other reasons. When the train is pulled with one or more handbrakes set, the metal wheels of the railroad car will be caused to flatten as they are dragged along the metal railroad track without the wheels turning. This flattening of the wheels is a dangerous condition and is very expensive to remedy since the entire wheel must then be removed from the freight car and replaced.
One invention directing toward reducing the risk of moving the train while one or more handbrakes is set is described in the 1993 patent issued to Sauer, U.S. Pat. No. 5,201,890. In the Sauer patent, a standard type handbrake has affixed to each of the handbrake units a hydraulic cylinder. A pair of hydraulic cylinders are interconnected for each car so that releasing the brake at one end of the car will also actuate the release for the handbrake unit at the other end of the car. Return springs automatically return the release handles at both ends to their non-actuated positions. While this particular device precludes having both handbrakes in the locked position as the car is pulled, it would insure that both handbrakes are released if only one handbrake at one end of the car is manually released. However, Sauer does not provide for the simultaneous and automatic release of all handbrakes once one mechanism is released.
It is an object of this invention to provide a simple yet automatic system for releasing the entire handbrake system of a railroad train once a pre-determined pressure is reached on the train's separate air brake system. Another object of this invention is to insure that a railroad train is not run with any of the manual handbrakes on the individual cars in the locked position.
A still further object of this invention is to provide a means for reducing wear on railroad wheels by automatically insuring that the train's air brake system will automatically release the separate handbrake systems once a set running pressure is achieved. Other and further objects of this invention will become apparent upon reading the below described Specification.